In the opening act of the 1924 Sigmund Romberg operetta “The Student Prince,” a group of Heidelberg University students are hoisting their steins in a local pub while singing the famous “Drink, drink, drink!” song.

Fast-forward 90 years and another group of singers are belting out the same tune — and others — in a pub, this time in New Orleans.

Like the students celebrating the joys of life and love in the operetta and the film it spawned, the singers in New Orleans are celebrating life but with an added purpose.

As members of the Opera on Tap ensemble, they are promoting a centuries-old, yet oft-misunderstood, performing arts form.

Opera on Tap, an educational arm of the New Orleans Opera Association, brings anywhere from four to six opera singers and a piano accompanist to two drinking and dining establishments in New Orleans and one on the North Shore.

All performances are free and open to the public.

Year-round, the troupe performs 90-minute sets on the third or fourth Wednesday of each month at the Four Points by Sheraton Hotel in the French Quarter.

Also, four times a year, it performs at the Rusty Nail in the Warehouse Arts District and at the Abita Brew Pub in Abita Springs.

The repertoire consists of arias, duets and ensemble pieces from popular operas and operettas, as well as a mix of familiar Broadway show tunes.

All four voice categories — bass, tenor, mezzo-soprano (alto) and soprano — are represented.

The lineup of singers, ranging from seasoned professionals in the New Orleans Opera Chorus to talented college voice students, varies from one performance to another.

Carol Rausch, the longtime chorus master, music administrator and education director for the New Orleans Opera Association, founded the local chapter of the Opera on Tap organization, which includes 15 other chapters in major U.S. cities.

Following the lead of the parent organization headquartered in New York, OOT-New Orleans is in its seventh year.

“This is a great way to demystify opera for people who wouldn’t normally be opera fans,” Rausch explained. “Opera on Tap is a viable thing for keeping the visibility of the art form out there where people can see, hear and enjoy it — even participate in it sometimes.”

As examples, Rausch noted that members of the audience may be invited to sing along with some of the songs they might be familiar with, such as “The Drinking Song” from “The Student Prince.”

Or, on occasion, a man might be randomly selected from the crowd to sit onstage for a mock shave, while a male and female singer regale him with a duet from Rossini’s “The Barber of Seville.”

“We perform in a very friendly atmosphere, and I really believe in what it can accomplish,” Rausch said. “You just never know when somebody might come and hear us and like what they’re hearing. We’ve even had people become season subscribers (to New Orleans Opera) after seeing one of our performances.”

One such “opera convert” is Debbie Fagnano, the longtime calliope player aboard the steamboat Natchez.

“I went to the first Opera on Tap at the Rusty Nail and I had such a good time,” Fagnano said. “I just thoroughly enjoyed it. As a result, I got to see opera in a new light.”

This coming-together had fortuitous consequences in two ways.

Not only did Fagnano become a season subscriber, but she also arranged for Opera on Tap to stage performances on the boat, something it has done about half a dozen times.

“The performers enjoyed it and people on the boat enjoyed it, so we’ve had them come back every year,” Fagnano said. “I just love it. I’ve gotten to meet opera people from the maestro (Robert Lyall) to professional singers to students.”

Rausch, who also teaches voice at Loyola University, sometimes uses some of her students, as well as students from other universities in New Orleans, Baton Rouge, Hammond and even nearby Mississippi.

“OOT concerts are a great way to showcase and further develop the talents of these voice students, in addition to helping out locally based professional singers who are seeking a performance outlet. They’re fun for the audience, but just as much fun for the performers.”